Secure Shell (SSH) servers listen on what port and protocol?

A.
TCP port 20

B.
TCP port 21

C.
TCP port 22

D.
TCP port 23

Explanation:
Answer C is correct; SSH servers listen on TCP port 22.

Incorrect Answers and Explanations: A, B, and D: Answers A, B, and D are incorrect. FTP uses TCP ports 20 and 21. Telnet uses TCP port 23.